Nokia Lumia 1520 - Which features are available in Skype for Windows Phone app?

Features for the Skype for Windows Phone app include, free Skype-to-Skype audio and video calling over 4G, 3G and WiFi, calling to landlines and mobile numbers at Skype great rates (i.e. Skype Out), 1:1 and multiparty instant messaging, among others.